LAND SURVEY TERMS
GLOSSARY OF U.S. BUREAU OF LAND MANAGEMENT SURVEYING AND MAPPING TERMS M
Land Survey Terms, A convenient source for our clients and website visitors
M
M – Mile, as marked on monuments and/or accessories.
m – Meter.
MAP/MYP – Management Action Plan/Multi-Year Program (A BLM Planning System-not a mapping term).
MAT S (Land Status Records) – Material site.
M&B – (Land Status Records) – Metes and Bounds.
MC – Meander Corner.
MC (Land Status Records) – Mineral Certificate; Also Min Cert.
MCOA or MOA (Land Status Records) – Mining Claim Occupancy Act.
M & P FACTORS – Tables used for computing arcs on the meridians and parallels. See M & P FACTOR*.
MSL – Mean Sea Level.
MSS – Multispectral Scanner Subsystem.
MAGAZINE – A container for rolled film or photographic plates attached to the camera body.
MAGNETIC AZIMUTH (OR BEARING) – Azimuth (or bearing) referred to magnetic north or south.
MAGNETIC DECLINATION – The bearing of magnetic north at a particular date. See MAGNETIC
VARIATION and MAGNETIC DECLINATION*.
MAGNETIC NORTH – The direction indicated by the north end of a magnetized needle under influence of the
earth’s magnetic field and free of local magnetic disturbance.
MAGNETIC VARIATION – Regular or erratic change in magnetic declination. Not interchangeable with
magnetic declination. See MAGNETIC VARIATION*.
MAIN SCHEME STATION – 1) (USGS) One of the principal stations of a triangulation arc or net, observed,
computed, and adjusted in accordance with the general specifications for the project, contributing to the
overall strength of the system. 2) (NGS) A station through which basic data are carried for the continued
extension of a survey system.
MAKELINE – A scale line (or one of a corresponding pair of lines) furnished to a process camera operator with
instructions for a ratio of enlargement or reduction.
MANUSCRIPT MAP – The original drawing of a map as compiled or constructed from various data, such as
ground surveys and photographs. Usually, place and feature names are not included.
MAP – A representation on a plane surface, at an established scale, of the physical features (natural, artificial, or
both) of a part or whole of the earth (or any celestial body) by means of symbols and labels and with the means
of orientation indicated. A map may emphasize, generalize, or omit the representation of certain features to
satisfy specific requirements. The type of information which a map is designed primarily to convey is frequently
used, in adjective form, to distinguish it from maps of other types. See BASE MAP, COMPILED MAP,
ENGINEERING MAP, GENERAL PURPOSE MAP, PLANETABLE MAP, PLANIMETRIC MAP,
PLAINMETRIC BASE MAP, QUADRANGLE MAP, RECONNAISSANCE MAP, SHADED RELIEF MAP,
SPECIAL PRINTING MAP, SPECIAL PURPOSE MAP, and TOPOGRAPHIC MAP.
MAP OF STANDARD FORMAT – A map with dimensions, layout, lettering, and symbolization in accordance
with the specifications for the series.
MAPPING ANGLE – The correction to be applied to geodetic azimuth before plotting an azimuth on a map
projection.
MAPPING CAMERA – A camera specifically designed for use in surveying. Generally, the term indicates a high
precision camera although camera requirements for aerotriangulation may exceed the capability of a mapping
camera.
MAP PROJECTION – A system of lines on a plane representing a corresponding system of imagery lines on an
adopted terrestrial or celestial datum surface; also, the mathematical concept of such a system. For maps of the
earth, a projection consists of (a) a graticule of lines representing parallels of latitude and meridians of longitude,
or (2) a grid. A map projection may be derived by geometric construction or by mathematical analysis.
Projections derived by mathematical analysis are generally used for maps constructed with survey data. See
ALBERS CONICAL EQUAL AREA PROJECTION, LAMBERT CONFORMAL CONIC PROJECTION,
MERCATOR PROJECTION, OBLIQUE MERCATOR PROJECTION, ORTHOGRAPHIC PROJECTION,
POLYCONIC PROJECTION, STEREOGRAPHIC PROJECTION, TRANSVERSE MERCATOR
PROJECTOR, UNIVERSAL TRANSVERSE MERCATOR PROJECTION, and POLAR STEREOGRAPHIC
PROJECTION.
MAP REVISION (USGS) – Updating, improving, and/or correcting map content at the same scale. A complete
revision consists of the correction of all deficiencies in planimetry and relief features, including improvement of
accuracy, vertical and/or horizontal, to result in a class 1 map that meets current specifications in all respects.
See also STANDARD REVISION, LIMITED REVISION, and INTERIM REVISION.
MAP SCALE – The relationship between a distance on a map and the corresponding distance on the earth. Map
scale may be expressed as an equivalence, usually by different units (1/63,360 or 1:63,360); or graphically, as a
bar scale. See FRACTIONAL SCALE and REPRESENTATIVE FRACTION.
MAP SERIES – (USGS) A family of maps conforming generally to the same specifications or having some
common unifying characteristics. The term ”National Topographic Map Series” is used to designate collectively
the several quadrangles and other map series of the United States and its dependencies. The individual series are
7.5 Minute Series – Covers 7.5 minutes of latitude and 7.5 minutes of longitude.
Puerto Rico – 7.5 Minute Series – Bilingual & Metric. 15-Minute Series – Covers 15 minutes of Lat.
& Longitude.
Alaska 1:63,360 series covers 15 minutes in latitude. 1:250,000 series generally covers 1° in latitude
and 2° in longitude.
Metropolitan Area Series – Selected cities
National Park Series
State Series – Available as base maps
Topographic and shaded
United States Series –
International Map of the World Series – U.S. portion
30-minute series – now being superseded
1° degree series – now superseded by the 1:250,000 series.
Alaska Reconnaissance Series is now being superseded by the 1:250,000 series.
MARGINAL, DATA – Information on the margin of maps, explaining symbols, geographic coordinates, and other
data portrayed by the map.
MARGINAL TICK – See GRID TICK.
MARINE LEAGUE – A measure of distance commonly employed at sea, being equal to the one-twentieth part of a
degree of latitude, or three geographical or nautical miles.
MARK – 1) A definite object ( such as an imprinted metal disk) used to designate a survey point. Usually used with
qualifying terms such as a station mark, reference mark, azimuth mark, or benchmark. Sometimes refers to the
entire survey monument. 2) A call is used to indicate the instant of observation. 3) A call is sometimes used by the
rear chainman to indicate he is on the correct reading.
MARSH – Low-lying wet ground ordinarily covered with water. See SALT MARSH* and SWAMP.
MATCH LINE – 1) The edge of an individual photograph in a mosaic. 2) The line at the edge of a mapped area.
MEANDER LINE – A traverse along the approximate mean high water line of a permanent natural body of water.
See MEANDER LINE*.
MEAN ERROR – An ambiguous term sometimes used to denote average error, error of the mean, or root-mean-
square error.
MEAN REFRACTION – The average refraction effect on vertical angles in stated conditions of temperature,
humidity, and barometric pressure.
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meter. 2) Reading device on a theodolite.
MICRON (SYMBOL) – Unit of length exactly 10- meters, 10- centimeters, (the term is now replaced by
micrometer).
MICROWAVE – Of, or pertaining to, radiation in the microwave region.
MICROWAVE REGION – Commonly, that region of the radio spectrum between approximately 1000 and
300,000 megahertz. Corresponding wavelengths are 30 centimeters to 1 millimeter.
MID-LATITUDE – 1) The latitude of the midpoint of a survey line. 2) The average of the latitude values for the
endpoints of a straight line or a geodesic.
MILITARY GRID – A rectangular grid, coordinate, or reference system placed on a map projection to facilitate
location and identification of map data for military purposes. The Universal Transverse Mercator (UTM) grid is
used on maps at scales of 1:250,000 and larger between 80° north and 80° south. Beyond the 80° parallels the
Universal Polar Stereographic (UPS) grid is used.
MINE SURVEY – A survey to determine the position and dimensions of underground workings and the associated
improvements and boundaries. See MINE SURVEY* and MINERAL SURVEY*.
MINERAL MANAGEMENT MAP SERIES – A BLM compilation of planimetric and Land Status Data
consisting of SURFACE MANAGEMENT MAPS and SURFACE-MINERALS MANAGEMENT MAPS.
MISCLOSURE*.
MISMATCH – The condition of map detail displacement along neatlines.
MODEL – A 3-dimensional image of the terrain seen when a pair of overlapping photographs are viewed
stereoscopically. When the model is correctly oriented to the horizontal and vertical datums, the terrain is
accurately represented in miniature.
MODEL SCALE – The relationship between a distance measured in a model and the corresponding distance on the
terrain.
MONOCOMPARATOR – An optical instrument for the measurement of coordinates on a photograph that employs
one eyepiece (rather than stereo viewing). See COMPARATOR.
MOSAIC – An assembly of aerial photographs whose edges have been feathered and matched to form a continuous
photographic representation of a portion of the earth’s surface. Maps can be mosaiced for compilation purposes.
See CONTROLLED MOSAIC, UNCONTROLLED MOSAIC, and FILM MOSAIC.
MOSAICKING – The process of making composite photographs or maps.
MOUNTAIN – A mass of land considerably higher than its surroundings, and of greater altitude than a hill; an
eminence is often considered a mountain rather than a hill when its elevation from the foot to the summit is well
over 1,000 ft., but the distinction is arbitrary. The summit area of a mountain is small in proportion to the area of
its base; in this respect, it differs from a plateau.
MOUNTAIN GROUP – A group made up of several or many mountain peaks, or short mountain ridges. The
The Catskill Mountains and the Black Hill are examples.
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MOUTH – The exit or point of discharge of steam into another stream or lake or sea.
MUD LUMPS – Swellings of bluish-gray clay forming small islands of an acre or more, with a height of 5 to 10
feet above sea level found at the mouths of the Mississippi; apparently caused by the pressure of surface deposits
upon buried clays.
MULTIBAND – Simultaneous use of two or more sensors to obtain imagery from different portions of the
reflectance portion of the electromagnetic spectrum (most commonly used in connection with black and white
photography).
MULTIPLE BAND – Images formed usually simultaneously in more than one portion of the photographic region
of the electromagnetic spectrum and analyzed jointly.
MULTIPLEX PLOTTER – A stereoscopic plotting instrument of the double-projection anaglyphic type which
uses reduced-scale diapositives, stationary lamp houses with condensing lenses, and projectors designed for an
an optimum projection distance of 360 mm.
– Designates imagery formed, usually simultaneously, in more than one spectral region and
analyzed jointly. The simultaneous use of two or more sensors to obtain imagery from different portions of the
electromagnetic spectrum.
MULTISPECTRAL SCANNER SUBSYSTEM (MSS) – The ERTS 1 equipment which oscillates a flat mirror
between the field of view and the telescope and which gathers data on four bands simultaneously.
MUSKEG – Arctic alluvial areas with insufficient drainage over which moss has accumulated to a considerable
depth. These swamps are usually covered with tamarack and fir trees. In places the surface is broken by tall
hummocks.
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